Post-effective amendment to a registration statement that is not immediately effective upon filing

Commitments and Contingencies - Additional Information (Detail)

v2.4.1.9
Commitments and Contingencies - Additional Information (Detail) (USD $)
1 Months Ended 12 Months Ended
Oct. 31, 2013
Sep. 30, 2014
Sep. 30, 2013
Commitments And Contingencies [Line Items]      
License Maintenance Costs   $ 35,000arth_LicenseMaintenanceCosts $ 25,000arth_LicenseMaintenanceCosts
Payments For Rent Per Square Foot 26arth_PaymentsForRentPerSquareFoot    
Payments For Rent Monthly Payments 5,031arth_PaymentsForRentMonthlyPayments    
Payments For Security Deposits 10,062arth_PaymentsForSecurityDeposits    
Contractual Obligation   195,000us-gaap_ContractualObligation  
Patents      
Commitments And Contingencies [Line Items]      
Finite-Lived Intangible Asset, Useful Life   20 years  
MIT Licensing Agreement      
Commitments And Contingencies [Line Items]      
Contractual Obligation   $ 45,000us-gaap_ContractualObligation
/ dei_LegalEntityAxis
= arth_MitLicensingAgreementMember
$ 35,000us-gaap_ContractualObligation
/ dei_LegalEntityAxis
= arth_MitLicensingAgreementMember